A high-rise hotel in Cardiff city centre has failed a cladding safety test.
A report to South Wales Fire and Rescue Authority states a hotel and a block of flats in the capital had not met "combustibility requirements".
It means that to date 12 buildings in the region have failed the tests.
The authority refused to tell BBC Wales which hotel it was but said the cladding was being removed.
Cardiff council said it had not been informed about the failure to meet building regulations guidance for cladding systems at either of the sites in the city.
According to a report put before South Wales Fire and Rescue Authority there are now 12 buildings in the area which have not met the standards required in the wake of the Grenfell disaster.
As of January, 206 tower blocks of six storeys or more owned by social and private landlords, hotels and student accommodation in south Wales have been checked by fire safety officers.
Fire staff have been visiting the sites of the private high-rise flats that failed tests to check water availability in case of a blaze, which they said needed "some remedial work".
The report also states firefighters are to get extra training for high-rise blazes, which is expected to be held at a training facility in the West Midlands.
A fire authority spokeswoman said it had been carrying out a risk-based inspection programme speaking to local authorities, management companies and residents to ensure properties were safe.
"Operational and community safety personnel have conducted safe and well visits, home fire safety checks and tested water provisions for firefighting should an incident occur," she added.
"A review of operational response has also been carried out and the decision has been made to increase the number of appliances that would initially respond to an incident of this nature."
A Welsh Government spokesman said: "We are working to identify all high-rise buildings where an ACM product forms part of the cladding system.
"So far 12 private residential sector buildings and three high-rise buildings in the social housing sector have been identified as having ACM systems which correspond with those which have failed large-scale combustibility tests.
"We have also been made aware that a high-rise hotel in Cardiff has an ACM cladding system, which would appear to correspond with a system which failed large-scale tests."